Thin-walled metal containers are popular for packaging certain items where the packaging is intended to have a degree of permanency. They are advantageous in that they provide good protection for the content, and they provide the opportunity to permanently print attractive designs on the container themselves or to have the designs embossed therein. The containers thus can be used for long periods of time. In the case where the contents are consumed after a short period, the containers are often kept for other storage purposes. Further, a metal container used for packaging retail products can provide an upscale or high-end feel to the packaging of the product that is being sold.
Thin-walled metal containers are typically made from thin metal sheets by deep drawing. Some of them have separable lids and bottoms. Others, including many low profile containers, have hinged lids that are not separable from the bottoms. Both hinged and non-hinged metal containers share the aspects that the lids are not identical to the bottoms because they are intended to interfit. Thus, two different tool sets are normally required to form a container, one for making the container lid, the other for the bottom. Typically, the bottom has an edge which is inwardly rolled or hemmed to avoid exposing raw metal edges, and sometimes has a ledge formed at the upper part to serve as a receiving area/stop for the lid. The lid or cover typically has a rolled or hemmed edge to also avoid exposing raw metal edges, and that edge is typically rolled outwardly, to leave the inside wall of the lid available to fit the container bottom. In the case of a hinged container, the lid further has a hinge half that interfits and an associated hinge half of the container bottom.
The hinged connection between the lid an the bottom of a hinged container facilitates repeated opening and closing of the container and also eliminates the possibility of mislaying the container lid. Hinged containers, however, are generally more expensive to make than non-hinged containers with separable container halves, due to the cost involved in forming the hinges. For example, the hinge on a low-profile metal container is typically intricately formed from metal tabs extending from the sides of the container halves. To form such a hinge, the sheet metal blank from which a container half is formed has to be processed to form the tabs, and the tabs are then rolled or otherwise processed to form a hinge half. Although the exact configuration of hinges on hinged metal containers may differ, the formation of such hinges generally requires extra metal processing steps and more complicated tool sets than those required for non-hinged containers.
Attempts to overcome the problems of trying to connect the lid and bottom of hinged and non-hinged metal containers have been tried. More particularly, U.S. Pat. No. 5,782,371 to the instant assignee of the present application attempts to provide a plastic hinge member that couples a container lid to a container bottom. The hinge member includes a living hinge between a partial segment and a full ring segment. The partial ring segment pivots relative to the full ring segment via the living hinge. Only a portion of a rolled or formed edge of the container lid is engaged by the partial segment while an entire portion of the other one of the container bottom or container lid is received or engaged by the full segment. In the closed position, the container lid or container body that is engaged with the partial ring segment, includes a portion that is engaged with a portion of the full ring segment. Thus, in this device, the full ring segment engages both of the container lid and container bottom. Further yet, the partial ring segment and full ring segments define channels that completely receive the rolled edges of the top and bottom of the container such that the plastic hinge member extends laterally outward beyond the metal container on all of the sides of them metal container.
The present invention relates to improvements over the present state of the art for hingedly connecting two metal container halves together that generally have similar shapes.